• 전기학회논문지
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• 제59권3호
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• pp.609-613
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• 2010

In this paper, we optimized and simulated the heatsink of 75W LED module for street lighting and evaluated the optical properties with the manufactured heatsink. the structure of LED package make simple as chip and heatslug and thermal flow is analyzed by using the FEM(Finite Element Method) with CFdesign V10. Also, we measured the temperature of heatsink and evaluated the optical properties with infrared thermal image camera and integrated sphere system for luminous flux in $1\;[m^3]$ box. As results, Heatsink optimized in 3 mm pin thickness, 6 mm base thickness and 16 number of pin count by using Heatsink-designer and got the results which is the temperature of $47.37\;[^{\circ}C]$ and thermal resistance of $0.48407\;[W/^{\circ}C]$. In thermal flow simulation, the temperature of heatsink decreased from $51.54\;[^{\circ}C]$ to $51.51\;[^{\circ}C]$ and the temperature of heatsink by the time in real measurement decreased from $47.03\;[^{\circ}C]$ to $46.87\;[^{\circ}C]$. Moreover, we improve 0.68 % in the decreased ratio of the luminous flux.

• 비파괴검사학회지
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• 제30권2호
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• pp.110-115
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• 2010

발전용 밸브 내부의 누설은 냉각 기능 상실 및 방사선물질 방출 동 안전계통의 성능 저하와 수많은 에너지 손실 등 발전소 운전에 막대한 손상 및 사고를 초래하게 된다. 본 논문은 신뢰성 높은 진단 방법 개발을 위하여 국내 원자력발전소 2차계통의 누설 발생 또는 내부 부품의 손상이 발생할 수 있는 밸브를 대상으로 현장시험 및 모의누설실험시의 적외선열화상 측정 실험을 수행함으로써 단일계측방식의 불확실성을 제거하고 향후 누설진단에 대한 확대 적용을 도모하고자 하였다. 발전소 현장시험 및 밸브 모의누설시험시의 밸브 누설 상태에 따른 적외선열화상 이미지 측정 실험을 통하여, 적외선열화상 측정 방법은 밸브 누설 상태의 과정을 신속하고 정밀하게 측정 가능하며 향후 많은 종류의 밸브 누설진단에 활용함으로써 누설에 따른 막대한 에너지 손실 및 사고 예방의 유용한 기법으로 확대 적용이 가능할 것으로 생각된다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.471-473
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• 2002

Public concerns associated with the electromagnetic field (EMF) exposures from mobile phones on human body are increased. Although studies on the effects of the EMF exposures on human have been carried out for a long time, it is not proved yet whether the EMF effect is harmful or not. Based on the scientific results by experts, EMF exposure limits have been regulated as a precautionary approach on the assumption that the EMF effect may be harmful. It is well known that absorbed EMF can be transformed into heat within biological tissues and that thermal effects are related with the specific absorption rate (SAR) distribution. However, the relative magnitude and distribution of the energies are not well defined. Although there is comprehensive information of the thermal effects, most of them come from animal and in vitro studies. Considerable efforts have been made to analyze the EMF absorption model while the actual temperature in the human body has been rarely measured. Temperature changes on the face of a healthy male volunteer were studied. A digital mobile phone of 1.8GHz was used. A digital infrared imaging system (IRIS-5000, Medicore, Seoul, Korea) was applied to take infrared pictures of the face every minute while the volunteer talked over the mobile phone for 20 minutes. The specification of the imaging system was as follows: Temperature resolution = 0.1$^{\circ}C$; Range of temperature measurement = 17～40$^{\circ}C$; Pixel size = 0.9mm ${\times}$ 0.9mm; Frame time = 2.6s; Active temperature of detector = 77$^{\circ}$K. The result showed that temperature of the ear region was increased during the phone call and the region of the temperature increase on the face was expanded as the phone call time increased. Further study is necessary to investigate the temperature rise analytically and quantitatively.

• 한국기계가공학회지
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• 제18권9호
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• pp.44-51
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• 2019

Three types of samples with defects were measured by lock-in med-IR (infrared) thermography with various lock-in frequencies for different materials. The lock-in method can be used to detect defects when an external energy source is applied to the object, the non-uniformity of the incident thermal energy distribution is eliminated, and the camera's measurement cycle is synchronized with the load cycle of the incident energy source. For inspecting samples with defects, results of thermal images are analyzed when three types of materials, i.e., SM45C, STS316L, and AL6061 are tested and three lock-in frequencies, i.e., 0.08, 0.1, and 0.12 Hz are applied. In this study, the optimal lock-in frequencies were determined by comparing the results of each material and lock-in frequency measured using the mid-IR camera.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.864-867
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• 2006

Thermal infrared images of Landsat-5 TM and Landsat-7 ETM+ sensors have been unrivalled sources of high resolution thermal remote sensing (60m for ETM+, 120m for TM) for more than two decades. Atmospheric effect that degrades the accuracy of Sea Surface Temperature (SST) measurement significantly, however, can not be corrected as the sensors have only one thermal channel. Recently, MODIS sensor onboard Terra satellite is equipped with dual-thermal channels (31 and 32) of which the difference of at-satellite brightness temperature can provide atmospheric correction with 1km resolution. In this study we corrected the atmospheric effect of Landsat SST by using MODIS data obtained almost simultaneously. As a case study, we produced the Landsat SST near the eastern and western coast of Korea. Then we have obtained Terra/MODIS image of the same area taken approximately 30 minutes later. Atmospheric correction term was calculated by the difference between the MODIS SST (Level 2) and the SST calculated from a single channel (31 of Level 1B). This term with 1km resolution was used for Landsat SST atmospheric correction. Comparison of in situ SST measurements and the corrected Landsat SSTs has shown a significant improvement in $R^2$ from 0.6229 to 0.7779. It is shown that the combination of the high resolution Landsat SST and the Terra/MODIS atmospheric correction can be a routine data production scheme for the thermal remote sensing of ocean.

• International Journal of Internet, Broadcasting and Communication
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• 제16권2호
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• pp.50-58
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• 2024

Body temperature plays an important role in medicine, some diseases are characterized by changes in human body temperature. Monitoring body temperature also allows doctors to monitor the effectiveness of medical treatments. Accurate body temperature measurement is key to detecting fevers, especially fevers related to infection with the SARS-CoV-2 virus that caused the recent Covid-19 pandemic in the world. The solution of measuring body temperature using a thermal camera is fast but has a high cost and is not suitable for some organizations with difficult economic conditions today. Use a medical thermometer to measure body temperature directly for a slow rate, making it easier to spread disease from person to person. In this paper, we propose a completely automatic body temperature measurement system that can adjust the height according to the person taking the measurement, has a measurement logging system and is monitored via the internet. Experimental results show that the proposed method has successfully created a fully automatic human body measurement system. Furthermore, this research also helps the school's scientists and students gain more knowledge and experience to apply Internet of Things technology in real life.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.146-148
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• 2005

This study investigates to detect sea surface temperature (SST) and land cover change after tide embankment construction using Landsat Thematic Mapper (TM) thermal infrared (TIR) band data at Shihwa Lake and surrounding area. SST measurement is important for studies of both the structure of the ocean and as the thermal boundary between the ocean and the atmosphere. The TIR band of TM images can be used to detect SST change whose shoreline is complicated and narrow like the study site. The purpose of this study is to estimate SST and land cover change at Shihwa Lake and surrounding area.

• 대기
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• 제25권4호
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• pp.601-610
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• 2015

This study measured the emissivity spectra of 5 major rock-forming minerals using a Fourier Transform Infrared (FT-IR) spectrometer in the spectral region of $650{\sim}1400cm^{-1}$. The mineral samples are quartz, albite, bytownite, anorthite, and sandstone. We compared emissivity spectra measured in this study with spectra provided by Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Arizona State University (ASU). The spectral features of emissivity such as Reststrahlen Band (RB) and Christiansen Feature (CF) locations were compared. Results showed that both CF and RB locations of emissivity spectra measured in this study were similar to those from ASTER and ASU. In the case of quartz, the RB was occurred in the region of $700{\sim}850cm^{-1}$ and $1050{\sim}1250cm^{-1}$. The spectral position of emissivity peak was in good agreement with the location of ASTER and ASU. For plagioclase (albite, bytownite, and anorthite), the spectral location of CF was shifted toward larger wavenumber and the emissivity value was increased in the region of $870{\sim}1200cm^{-1}$ with Ca percentage. The CF of anorthite and bytownite was occurred at $1245.79cm^{-1}$, and that of albite was occurred at $1283.79cm^{-1}$. We also confirmed that emissivity feature of sandstone includes both emissivity features of quartz and calcite. However, there were some differences in the magnitude of emissivity and locations of RB and CF. These were due to the differences in measurement methods, and differences in particle size and temperature of samples.

• 한국지리정보학회지
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• 제9권4호
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• pp.224-232
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• 2006

본 연구는 Landsat Thematic Mapper (TM) 영상의 열적외선 (Thermal Infrared: TIR) 밴드 자료를 이용하여 시화호와 그 주변지역의 해수면 온도 (SST: sea surface temperature)를 검출하고, 시화방조제 공사 후의 토지피복변화를 파악하기 위해 수행되었다. 해수면 온도의 측정은 해양체계 뿐만 아니라 해양과 대기 사이의 열적인 경계범위 연구에 있어 중요하다. 1970년대 이후, AVHRR (advanced very high resolution radiometer)과 Landsat TM (Thematic Mapper)과 같은 인공위성 영상의 원격탐사기법을 이용한 해수면 온도의 추출이 이루어졌다. 그러나 AVHRR 영상은 우리나라의 서해안 지역과 같은 매우 복잡한 해안선을 가지고 있는 지역에서는 조악한 공간 해상도로 인해 해수표면온도 추출에 한계가 있다. Landsat TM 위성영상은 본 연구지역과 같이 복잡하고 좁은 해안지역의 해수면 온도 추출에 유용하게 사용된다고 판단된다.

• 한국방사선학회논문지
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• 제11권4호
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• pp.273-278
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• 2017

적외선 체열검사를 시행한 $L_4-L_5$ 추간판 탈출증 환자의 45명 중 여자가 더 많았으며, 연령은 50대가 가장 많았다. 피절 분포표에 따라 측정한 결과, ${\chi}^2-test$에서는 성별과 나이에 따라서 유의한 차이를 보이지 않았다(p>0.05). $L_4-L_5$ 추간판 탈출증 환자의 ROI 온도를 측정한 부위는 후면 오른쪽 정강이뼈 뒤쪽의 온도가 가장 높았으며, 후면 왼쪽 정강이뼈 뒤쪽-전면 오른 무릎아래-전면 왼 무릎아래의 순이었다. 측정부위에 따라 유의한 차이를 보였다(p<0.05). 나이에 따라서는 ${\chi}^2-test$에서는 나이에 따라 0.030을 유의한 결과를 보였다(p<0.05). 정상인의 평균 ROI 온도는 $31.20{\pm}0.58$, 환자의 평균 ROI온도는 $30.30{\pm}0.50$으로 온도 차이는 $0.66{\pm}0.59$로 나타났다. 환자의 ROI온도가 정상인과 차이가 나는 지 알아보기 위한 일 표본 t-검정결과, 유의확률이 0.03으로 0.05보다 작으므로 환자의 ROI온도는 $31.20{\pm}0.58$보다 낮게 나타났다(p<0.05). 앞으로의 과제는 온열환경에 따른 보정 테이타의 처리기술과 그것을 이용한 새로운 온열 인덱스의 개발이 필요하다고 사료된다. 따라서 데이타의 보정을 줄이기 위해서는 적외선 체열 진단 시 전처치가 무엇보다 중요하며, 이를 검사하는 방사선사는 환자를 측정 시 주의 깊은 관찰과 배려가 요구된다.